App icon and launch screen in iOS Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of an app icon in iOS apps?

An app icon visually represents the app on the device's home screen and app store. It helps users quickly identify the app among others.

beginner

What is a launch screen in an iOS app?

A launch screen is a temporary screen shown when the app starts. It gives users immediate feedback that the app is loading and improves perceived performance.

intermediate

Where do you set the app icon images in an Xcode project?

App icon images are set in the Assets.xcassets folder under the AppIcon image set. You provide different sizes for various device resolutions.

intermediate

How do you create a launch screen in an iOS app?

You create a launch screen by adding a LaunchScreen.storyboard file in Xcode and designing a simple UI that appears while the app loads.

intermediate

Why should launch screens avoid complex animations or heavy content?

Launch screens should be simple and static to load quickly and avoid delaying app startup. Complex content can slow down the launch and frustrate users.

Where do you place different sizes of app icons in an iOS project?

A In the main.swift file

B In the LaunchScreen.storyboard

C In the Info.plist file

D In the Assets.xcassets under AppIcon

App icons are managed in the Assets.xcassets folder inside the AppIcon image set.

What is the main role of the launch screen in an iOS app?

A To provide immediate visual feedback during app startup

B To display the app icon in full screen

C To replace the home screen after app launch

D To show a loading indicator while the app starts

The launch screen provides immediate visual feedback that the app is starting, improving user experience.

Which file type is commonly used to design the launch screen in Xcode?

A .storyboard

B .swift

C .plist

D .xcassets

Launch screens are designed using a storyboard file, typically named LaunchScreen.storyboard.

Why should app icons be provided in multiple sizes?

A To animate the icon on the home screen

B To support different device screen resolutions

C To allow users to choose their favorite icon size

D To reduce app size

Multiple icon sizes ensure the app looks sharp on all devices with different screen resolutions.

What should you avoid including in a launch screen?

A Simple static images

B App name text

C Complex animations or heavy content

D Background color

Complex animations or heavy content can delay app startup and should be avoided in launch screens.

Explain how to set up an app icon in an iOS app project using Xcode.

Think about where images are stored and why different sizes matter.

Describe the purpose and best practices for creating a launch screen in an iOS app.

Consider what users see when the app starts and how to keep it fast.

Practice

1. What is the main purpose of the app icon in an iOS app?

easy

A. To display the app's settings menu

B. To represent the app on the home screen and App Store

C. To show a loading animation when the app starts

D. To provide user notifications

Solution

1. Step 1: Understand what an app icon is

   The app icon is the image users see on their device's home screen and in the App Store.

2. Step 2: Identify the purpose of the app icon

   It visually represents the app so users can recognize and open it easily.

3. Final Answer:

   To represent the app on the home screen and App Store -> Option B

4. Quick Check:

   App icon = app representation [OK]

Hint: App icon shows your app's picture on the device [OK]

Common Mistakes:

• Confusing app icon with launch screen
• Thinking app icon controls notifications
• Believing app icon shows loading animations

2. Which file or folder is used to set the app icon images in an Xcode iOS project?

easy

A. Assets.xcassets/AppIcon.appiconset

B. Main.storyboard

C. Info.plist

D. LaunchScreen.storyboard

Solution

1. Step 1: Identify where app icons are stored

   App icons are placed inside the Assets.xcassets folder, specifically in the AppIcon.appiconset.

2. Step 2: Differentiate from other files

   LaunchScreen.storyboard is for launch screens, Info.plist holds app settings, and Main.storyboard is for UI layout.

3. Final Answer:

   Assets.xcassets/AppIcon.appiconset -> Option A

4. Quick Check:

   App icons = Assets.xcassets/AppIcon.appiconset [OK]

Hint: App icons live in Assets.xcassets, not storyboard files [OK]

Common Mistakes:

• Choosing storyboard files for app icons
• Confusing Info.plist with icon storage
• Not knowing Assets.xcassets purpose

3. Given the following code snippet in an iOS app project, what will the launch screen display when the app starts?

/* LaunchScreen.storyboard contains a centered image named 'LaunchImage' */
// No code changes to launch screen

medium

A. The image named 'LaunchImage' centered on the screen

B. A blank white screen

C. The app icon displayed full screen

D. An error because launch screen needs code

Solution

1. Step 1: Understand launch screen storyboard setup

   The LaunchScreen.storyboard has a centered image named 'LaunchImage'. This storyboard is shown while the app loads.

2. Step 2: Predict what appears on launch

   Since the storyboard shows the image centered, the launch screen will display that image centered on the screen.

3. Final Answer:

   The image named 'LaunchImage' centered on the screen -> Option A

4. Quick Check:

   Launch screen storyboard shows its content [OK]

Hint: Launch screen shows storyboard content, no code needed [OK]

Common Mistakes:

• Thinking launch screen shows app icon automatically
• Assuming launch screen is blank without code
• Believing launch screen requires Swift code

4. You set a launch screen storyboard but when running the app, the launch screen shows a black screen instead of your design. What is the most likely cause?

medium

A. The app's Info.plist is missing

B. The app icon images are missing

C. The storyboard file has syntax errors in Swift code

D. The launch screen storyboard is not assigned in the project settings

Solution

1. Step 1: Check launch screen assignment

   If the launch screen storyboard is not set in the project settings under 'Launch Screen File', the app shows a black screen on launch.

2. Step 2: Rule out other causes

   Missing app icons or Info.plist issues do not cause black launch screens. Storyboards do not contain Swift code, so no syntax errors apply.

3. Final Answer:

   The launch screen storyboard is not assigned in the project settings -> Option D

4. Quick Check:

   Launch screen file must be set in project [OK]

Hint: Always assign launch storyboard in project settings [OK]

Common Mistakes:

• Confusing app icon issues with launch screen problems
• Expecting Swift code in storyboard files
• Ignoring project settings for launch screen

5. You want your app to show a launch screen with a background color and a centered logo image. Which steps correctly set this up in Xcode?

hard

A. Write Swift code in AppDelegate to display the image and background color on launch

B. Add the logo image to Assets.xcassets and set it as the app icon; no storyboard needed

C. Create a LaunchScreen.storyboard with a view colored as background and an image view centered; assign this storyboard in project settings

D. Set the background color and image in Info.plist under launch screen keys

Solution

1. Step 1: Design launch screen in storyboard

   Create a LaunchScreen.storyboard file with a view that has the desired background color and add an image view centered with the logo image.

2. Step 2: Assign launch screen storyboard in project

   In Xcode project settings, set the 'Launch Screen File' to this storyboard so the system shows it on app launch.

3. Final Answer:

   Create a LaunchScreen.storyboard with a view colored as background and an image view centered; assign this storyboard in project settings -> Option C

4. Quick Check:

   Launch screen = storyboard design + project assignment [OK]

Hint: Use storyboard for launch screen design, assign in settings [OK]

Common Mistakes:

• Trying to set launch screen via Info.plist
• Confusing app icon with launch screen setup
• Attempting to use Swift code for launch screen UI